Web Animations: Extract an API for servicing animations

Source/core/animation/Animation.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 38 matching lines @@
 
     const AnimationEffect::CompositableValueMap* compositableValues() const
     {
         ASSERT(m_compositableValues);
         return m_compositableValues.get();
     }
 
     bool affects(CSSPropertyID) const;
     const AnimationEffect* effect() const { return m_effect.get(); }
     Priority priority() const { return m_priority; }
+    Element* target() { return m_target.get(); }
 
     bool isCandidateForAnimationOnCompositor() const;
     // Must only be called once and assumes to be part of a player without a start time.
     bool maybeStartAnimationOnCompositor();
     bool hasActiveAnimationsOnCompositor() const;
     bool hasActiveAnimationsOnCompositor(CSSPropertyID) const;
     void cancelAnimationOnCompositor();
 
 protected:
     // Returns whether style recalc was triggered.
@@ skipping 16 matching lines @@
     Priority m_priority;
 
     Vector<int> m_compositorAnimationIds;
 };
 
 DEFINE_TYPE_CASTS(Animation, TimedItem, timedItem, timedItem->isAnimation(), timedItem.isAnimation());
 
 } // namespace WebCore
 
 #endif